Before Sending Your Drawings: How to Help Your Manufacturer Understand Your Design the First Time
At Bergek CNC — an ISO 9001 certified 5-axis CNC machining manufacturer — we handle hundreds of customer drawings every month. Some come through perfectly; others cost hours of back-and-forth simply because of incompatible file formats or missing information.
So before you send your next model, here’s how to make sure your manufacturer reads it right the first time.
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1. A Common Situation from the Workshop
This happens almost every day in CNC manufacturing. A customer confidently sends over drawings and says, “Please quote as soon as possible.”
We open the file and— The system pops up: “Unrecognized file format.”
Sometimes it opens, but that’s not necessarily good news. Once imported, the surfaces crack, edges break, or faces don’t align properly. The model looks fine on screen, but internally it’s broken — wall thickness is off, surface data is missing, and volume readings become unreliable.
In such cases, we never waste time rebuilding geometry — it’s inefficient and inaccurate. The best way is to ask the customer to re-export the model in STEP format, which keeps all geometry and surface data clean.
It’s not anyone’s fault — different CAD programs speak different “languages.”
2. Why Some 3D Models Simply Don’t Work
There are many CAD tools used for precision custom parts — and each one saves files differently:
All of them are professional, but not all are cross-compatible. Models with freeform or complex surfaces often have broken faces, misaligned edges, or collapsed fillets after import. We’ve seen plenty of files that look fine but are full of “surface errors” — unusable for direct machining.
“Please export the model as a STEP (.stp) file and resend.”
STEP is the most universal format in the CNC machining services world. Think of it as the “common language” of manufacturing — no matter what CAD software you use, Bergek CNC can open it, measure it, and quote it accurately.
3. The Best Way to Send Your Drawings
Just remember this simple “golden combination” — it’ll save both sides a lot of time.
| Type | Recommended Format | Why |
|---|
| 2D Drawings | PDF + DWG/DXF | PDF makes it easy to check notes and dimensions; DWG/DXF allows direct measurement |
| 3D Models | STEP (.stp/.step) | Universal format that preserves geometry, curves, and surfaces |
| Not Recommended | STL, SLDPRT, IPT, etc. | STL lacks editable features; SLDPRT/IPT require specific software and often fail to import cleanly |
📎 Additional Tip: Always Attach a PDF Drawing
Many customers ask: “I’ve already sent the 3D model—why do you still need a 2D drawing?”
In reality, the 3D model only shows the shape, while the PDF drawing contains the key manufacturing requirements.
Surface finishing requirements
Tolerances and precision levels
Assembly direction or special machining notes
3D model shows the structure, PDF drawing shows the details.
Send both — and your CNC machining manufacturer can understand your design the first time.
4. Why This Makes Quoting Faster
When the files open correctly, our engineers at Bergek CNC can start the quoting process immediately:
Measure dimensions and volume → Estimate material cost;
Identify geometry and surface features → Evaluate machining complexity;
Check annotations and finishing requirements → Select the right process route;
Estimate time and cost → Generate an accurate quotation.
If a file won’t open or the model contains broken surfaces, we have to stop and ask for a new version — and that delay can easily cost a full day.
This isn’t about being picky — we just want to understand your design clearly and spend time optimizing your part, not fixing CAD data.
5. A Final Word from a Manufacturer’s View
Every designer has different habits — some use SolidWorks, others Fusion 360, AutoCAD, or ProE. But if you take one extra minute to export a STEP file and attach a PDF drawing, you’ll save everyone hours of unnecessary waiting.
Manufacturing is collaboration. When you send drawings in a format your manufacturer can understand, you’ll get faster, more accurate quotes — and smoother production.
If you’re not sure how to export your CAD files, don’t worry — just tell us what software you use, and we’ll share the correct export settings.
Ready to optimize your next design?
Visit www.szbergek.com to learn more about our custom CNC machining services, including 5-axis precision machining, CNC milling, and prototype manufacturing.
Because in the end, clear drawings are the first step toward high-quality parts.
